JP2002167504A - Flame retardant polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame retardant polyamide resin composition that does not contain triazine compounds and halogen compounds conventionally used and having various defects, that has excellent mechanical properties, especially, high impact properties, and that reduces problems encountered in the conventional manufacturing, processing and use to negligible levels, yielding a molded article with good appearance. SOLUTION: This flame retardant polyamide resin composition comprises (A) 25-60 wt.% of a polyamide resin which is at least partly crystalline, (B) 1-20 wt.% of a semi-aromatic amorphous polyamide resin, (C) 1-15 wt.% of an elastomer-modifying agent, (D) 30-50 wt.% of an inorganic reinforcingmaterial, (E) 5-20 wt.% of magnesium hydroxide, and (F) 0.5-10 wt.% of red phosphorus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant polyamide resin composition having good mechanical properties, especially excellent impact properties, high flame retardancy and good surface appearance properties. .

[0002]

2. Description of the Related Art Conventionally, techniques for making a polyamide resin difficult to twist include triazine compounds such as melamine cyanurate, halogen compounds, magnesium hydroxide, red phosphorus, or a combination of magnesium hydroxide and red phosphorus. A method of adding a flame retardant such as the above to a polyamide resin is known, but each has a problem.

[0003] In a resin composition containing a triazine compound,
During processing or fire, the generation of ammonia gas, amine-based gas, cyan gas, etc. cannot be suppressed. These compounds also have disadvantages in that a reinforced polyamide composition is unlikely to exhibit a sufficient flame retardant effect and has a low decomposition temperature.

[0004] The use of a halogen-based flame retardant has the problems of generating a toxic halogen gas during combustion and corroding processing machines such as kneading machines and molding machines during resin processing.

[0005] Magnesium hydroxide is a non-toxic non-halogen flame retardant, and has no problems such as toxic gas and corrosion of the processing machine. However, a large amount of magnesium hydroxide is required to exhibit sufficient flame retardancy. Then, there is a problem that mechanical properties such as strength and impact resistance are reduced. It is also difficult to obtain a good molded product appearance.

Red phosphorus can make a polyamide resin difficult to twist with a smaller amount than the other flame retardants described above. However, there is a problem that phosphine is generated during combustion, and the amount of red phosphorus added is reduced from the viewpoint of safety. It is desirable.

[0007] Therefore, regarding the idea of making the polyamide resin difficult to twist by the combined use of magnesium hydroxide and red phosphorus,
For example, it is proposed in JP-A-63-243158. However, according to this method, twisting is possible with a smaller amount of both red phosphorus and magnesium hydroxide than the single addition, but it is favorable if the combined use is added until sufficient flame retardancy is imparted. It is difficult to obtain a good molded product appearance, and has excellent mechanical properties, especially high impact properties,
At present, a composition having sufficient flame retardancy and good appearance of a molded article has not yet been obtained.

[0008]

DISCLOSURE OF THE INVENTION The present invention does not contain a triazine compound or a halogen compound which has been used conventionally and has various disadvantages, has excellent mechanical properties, particularly high impact properties, and can be produced by a conventional method. It is an object of the present invention to provide a flame-retardant polyamide resin composition having a good appearance of a molded article in which troubles during processing and use are reduced to a level at which there is no problem.

[0009]

Means for Solving the Problems Accordingly, the present inventors have:
In order to solve the above-mentioned problems, as a result of diligent studies, studies,
Finally, the present invention has been completed. That is, the present invention relates to (A)
Polyamide resin at least partially crystalline 25-60
% By weight, (B) semi-aromatic amorphous polyamide resin 1 to 20
% By weight, (C) 1 to 15% by weight of an elastomer modifier,
(D) 30-50% by weight of inorganic reinforcing material, (E) 5-20% by weight of magnesium hydroxide and (F) 0.5-10% by weight of red phosphorus
And a flame-retardant polyamide resin composition.

The present invention is a resin composition which does not contain a triazine compound, a halogen compound or the like which may cause problems in toxicity and processability. In addition, the combined use of red phosphorus and magnesium hydroxide reduces the amount of both flame retardants, reduces mechanical properties, suppresses problems such as phosphine generation, and provides a good method by adding the non-crystalline polyamide according to the discovery of the present invention. It is characterized in that a molded article appearance is obtained.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The partially crystalline polyamide resin (nylon) used as the component (A) in the present invention includes nylon 6 (polycapramid), nylon 66 (polyhexamethylene adipamide) and nylon 11 (poly-ω-undecamide), nylon 12 (poly-ω-dodecamide), nylon 46 (polytetramethylene adipamide), and the like. As a semi-aromatic polyamide resin, nylon 6T / 6 (6
T: polyhexamethylene terephthalamide), nylon 6T /
66, MXD6 (polymethaxylylene adipamide) and the like, and copolymers and blends containing these as components may be used without any particular limitation.

The amount of the partially crystalline polyamide resin (A) is from 25 to 60% by weight, preferably from 25 to 40% by weight, more preferably from 25 to 35% by weight, based on the whole composition. desirable. When the component (A) is less than 25% by weight,
Production by extrusion kneading becomes difficult, which is not preferable. If it exceeds 70% by weight, the required amount of the flame retardant increases, which is not preferable.

The semi-aromatic amorphous polyamide resin (B) used in the present invention is obtained from trimethylhexamethylenediamine, hexamethylenediamine, metaxylenediamine, terephthalic acid, isophthalic acid, and ε-caprolactam. It is a polymer, (1) having an amide group (-NHCO-) in the molecular chain, (2) having a glass transition temperature (Tg) of 100 ° C. or more, and (3) differential scanning calorimetry after heating the resin at 160 ° C. for 1 hour. The crystal melting amount is 3 J / g or less when the temperature is increased at a heating rate of 20 ° C./min by a DSC (DSC). Polymer with acid, trimethylhexamethylenediamine, terephthalic acid and ε-
Examples include a polymer with caprolactam, a polymer with terephthalic acid and isophthalic acid, hexamethylenediamine and ε-caprolactam, but are not particularly limited.

The compounding amount of the semi-aromatic amorphous polyamide resin (B) is 1 to 20% by weight, preferably 3 to 10% by weight, more preferably 5 to 10% by weight based on the total composition. desirable. If the content of the component (B) is less than 1% by weight, the appearance deteriorates, which is not preferable. If it exceeds 20% by weight, mold release failure at the time of molding occurs, which is not preferable.

The elastomer modifier as the component (C) used in the present invention is not particularly limited as long as it is a polymer having a tensile modulus of 200 MPa or less. For example, ethylene propylene
Rubber (EPR), ethylene copolymer such as ethylene propylene diene terpolymer (EPDM), ethylene vinyl acetate copolymer (EVA), styrene butadiene copolymer (SBE),
Styrene-ethylene-butadiene copolymer (SEBS), styrene copolymers such as styrene-isoprene copolymer (SIS), and other ester copolymers such as MMA-butadiene copolymer, and the like. Is particularly preferably EPR.

The compounding amount of the elastomer modifier (C) is 1 to 15% by weight, preferably 3 to 10% by weight, more preferably 6 to 10% by weight based on the whole composition. If the amount of the component (C) is less than 1% by weight, the effect of the modification is not sufficient, so that it is not preferable. If the amount of the component (C) exceeds 15% by weight, the appearance of a molded article is deteriorated.

Specific examples of the inorganic reinforcing material (D) used in the present invention include inorganic fibers such as glass fiber and carbon fiber, whiskers such as aluminum borate and aluminum titanate, and an average particle size. Is about 4-20 μm,
Milled fiber, which is a single fiber with a cut length of about 35 to 80 μm, etc., commonly used wollastonite and needle-like wollaston, plate-like talc, mica, unfired clay, amorphous and granulated Examples thereof include calcium carbonate, silica, and glass beads having a diameter, but are not particularly limited thereto. Preferably, the fibrous reinforcing agent has a mean particle size of about 5 to 15 μm and a cut length of about 1 to 5 mm.

The amount of the inorganic reinforcing material (D) is from 30 to 50% by weight, preferably from 35 to 50% by weight, more preferably from 40 to 50% by weight, based on the whole composition. If the content of the component (D) is less than 30% by weight, the effect of improving mechanical properties is not sufficient. Absent.

The magnesium hydroxide used as the component (E) in the present invention may be subjected to a surface treatment with a surface treatment agent, if necessary. Commercially available magnesium hydroxide can be used in the present invention with or without surface treatment. Magnesium hydroxide, which is finely granulated and has a diameter of 0.4 to 10 μm, is preferred, but is not limited thereto.

The amount of the magnesium hydroxide (E) is 5 to 20% by weight, preferably 5 to 15% by weight, more preferably 5 to 10% by weight, based on the whole composition. In addition, when the component (E) is less than 5% by weight, the flame retardancy is not sufficiently provided, so that it is not preferable. Absent.

The component (F) red phosphorus used in the present invention preferably has an average particle diameter of 1 to 50 μm. In particular, it is preferable that the surface treatment is performed as necessary to suppress the decrease in mechanical strength and the generation of phosphine, and that the surface of the particles be smooth. The surface properties are not particularly limited.

The compounding amount of (F) red phosphorus is 0.5 to 10% by weight, preferably 0.5 to 8% by weight, based on the whole composition.
%, More preferably 0.5 to 5% by weight. (F)
If the component is less than 0.5% by weight, it is not preferable because the flame retardancy is not sufficiently provided, and if it exceeds 10% by weight, problems such as generation of phosphine during production and molding are undesirably increased.

In the present invention, generally used lubricants, crystal nucleating agents, mold release agents, heat stabilizers, light stabilizers, colorants, etc. can be added according to each application and purpose, and particularly limited. It is not something to be done.

As a method for obtaining the composition of the present invention, a conventional method can be employed.
The component (F) and the like are blended in an arbitrary blending order at the above blending ratio and then melt-mixed. The melt mixing method can be any method known to those skilled in the art, and includes a single screw extruder,
A twin-screw extruder, kneader, Banbury mixer, roll, etc. can be used. Among them, it is desirable to use a twin-screw extruder. In addition, glass fibers, needle-like wollasts, and the like, which are easily broken during extrusion processing, are preferably introduced through the side opening of the twin-screw extruder, but are not particularly limited.

The composition of the present invention having the above constitution is
It is molded in various ways by known methods such as injection molding, extrusion molding, blow molding, etc., and is used for automobiles such as door mirror stays and cup holders, electric and electronic parts such as breaker parts and electric tools, and fishing tackle parts (sheets, reels, etc.). ) Are also used for sports / leisure use, civil engineering and construction. In the present invention, electric and electronic parts are particularly suitable.

[0026]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Each evaluation in the examples is a value obtained by the following method. Flexural strength: Measured according to ASTM D790. Flexural modulus: Measured according to ASTM D790. Flammability: Measured according to UL94. Izod impact strength: Measured according to ASTM D256. Gloss: Using a mirror-finished 100x100x3mmt mold, make a molded product at a resin temperature of 280 ° C and a mold temperature of 80 ° C, JIS
The gloss at an incident angle of 60 ° was measured based on Z-8714. (The higher the value, the better the gloss.)

Examples 1 and 2 and Comparative Examples 1 to 3 The raw materials shown in Table 1 were premixed in predetermined amounts, respectively, and then kneaded at 250 to 290 ° C. for 2 to 8 minutes using a biaxial kneading extruder. Each component was extruded and pelletized. Each of the obtained pellets was subjected to injection molding at a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C.
Each characteristic of each test piece obtained by injection molding was measured. Table 1 shows the results.

[0028]

[Table 1] In the table Nylon 6: Toyobo Nylon T-840 (trademark) Toyobo Co., Ltd. Nylon 6T / 6I: Grivory G21 (trademark) Ems Japan Co., Ltd. Elastomer modifier (EPR): Tuffmer MA8510 (trademark) Mitsui Chemicals Magnesium hydroxide: Kismar 5EU (trademark) Kyowa Chemical Co., Ltd. Glass fiber: vetrotex955 (trademark) manufactured by VETROTEX Red phosphorus: Nova Excel 140 (trademark) Rinka Chemical Co., Ltd. Magnesium stearate: NP -1500 (Trademark) manufactured by Tannan Chemical Industry Co., Ltd.

As is clear from Examples 1 and 2 and Comparative Examples 1-3, the combined use of magnesium hydroxide and red phosphorus
The amount of magnesium hydroxide required to express the flame retardancy of V-0 can be reduced, and furthermore, by incorporating a semi-aromatic amorphous polyamide, it has sufficient flame retardancy and mechanical properties, and good It can be seen that a molded article appearance can be obtained.

[0030]

As described above, according to the composition of the present invention having the above constitution, red phosphorus and magnesium hydroxide are used in combination, and a semi-aromatic amorphous polyamide is further added.
Since a flame-retardant polyamide resin can obtain sufficient mechanical properties and flame retardancy, and at the same time, can obtain a good surface appearance that can sufficiently withstand external uses, it greatly contributes to the industry.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 101: 00) C08L 101: 00) F term (reference) 4J002 AC08Y BB06Y BB15Y BC05Y BP01Y CL011 CL031 CL05X DA016 DA056 DA058 DE077 DE186 DE236 DJ016 DJ036 DJ046 DJ056 DK006 FA046 FD016 FD137 FD138 GM00

Claims (1)

[Claims] (A) 25 to 60% by weight of a polyamide resin at least partly crystalline, (B) 1 to 20% by weight of a semi-aromatic amorphous polyamide resin, (C) an elastomer modifier
1 to 15% by weight, (D) inorganic reinforcing material 30 to 65% by weight,
A flame-retardant polyamide resin composition comprising (E) 5 to 20% by weight of magnesium hydroxide and (F) 0.5 to 10% by weight of red phosphorus.